A prospective multicenter evaluation of 1,583 3i implants: 1- to 5-year data

PURPOSE: The purpose of this prospective multicenter study was to evaluate the efficacy of 3i threaded implants for the treatment of edentulous patients in a 1- to 5-year period. This article reports the total data and global results of 3 threaded designs of 3i implants: self-tapping, ICE, and Osseotite. MATERIALS AND METHODS: A total of 1,583 implants (619 ICE, 545 Osseotite, and 419 self-tapping) were placed between 1995 and 1999 in 528 patients at 13 European clinical centers. The average age of the patients was 53.6 years. Clinical and radiographic evaluations were performed annually for up to 5 years. RESULTS: Of the total implants, 707 were placed in the maxilla and 876 in the mandible. A total of 1,162 implants were placed in posterior segments. Forty-eight implants were lost to follow-up and 55 were failures. The most frequent prosthetic indication was the short-span fixed prosthesis (440 cases), followed by 172 single-tooth replacements, 56 long-span prostheses, and 4 overdentures. Radiographic evaluation after 6, 12, and 24 months of implant loading showed, respectively, mean crestal bone loss of 0.04 +/- 1.3 mm, 0.12 +/- 1.6 mm, and 0.2 +/- 1.7 mm. A cumulative survival rate of 96.5% was observed 5 years after implant placement, with 97.2% survival in the maxilla and 95.8% in the mandible. The survival rate was similar in anterior (96.7%) and posterior (96.5%) segments. DISCUSSION: A total of 55 failures were reported in this study with 47 early failures and 8 late failures. The rate of late failures is of utmost importance for the restorative dentist. CONCLUSION: This clinical study gives evidence of very high success rates using 3 threaded designs of 3i implants.     

Evaluating the clinical performance of the Osseotite implant: defining prosthetic predictability

A 5-year prospective, multicenter study is in progress at four private dental practices to determine the cumulative implant survival rate and prosthetic outcome when using the Osseotite dental implant in posterior maxillary and mandibular areas. An interim evaluation after 34.4 months of study progress is presented. A total of 219 Osseotite implants were placed in 74 patients (34 women and 40 men with a mean age of 57.8 +/- 15.2 years) using a conventional two-stage surgical protocol and 3- to 6-month healing time. Subsequently, patients were restored with fixed or removable restorations. Nineteen of the 74 patients reported smoking an average of 13.2 cigarettes per day. Restorative treatments included 40 single-unit restorations; 53 splinted 2-, 3-, 4-, and 5-unit implant-supported maxillary and mandibular prostheses; 4 full-arch fixed maxillary prostheses; 1 mandibular fixed/detachable hybrid prosthesis; and 1 mandibular overdenture. The mean time from implant placement to second stage surgery was 6.2 +/- 2.0 months; from restoration and implant loading to the most recent follow-up evaluation was 20.9 +/- 6.8 months. Of the 219 implants placed, three posterior maxillary implants developed infections and were removed prior to second stage surgery. No implant failures occurred at second stage surgery or after implant loading. Using the Kaplan-Meier method, the cumulative implant survival rate was 100% for anterior implants and 98.4% for posterior implants at 28.5 +/- 5.7 months. The cumulative postloading implant survival rate was 100% for both anterior and posterior implants. The results of this study indicate that the Osseotite dental implant achieved a high rate of integration that remained stable during nearly 2 years of implant function. In addition, because no postloading implant failures have occurred, the Osseotite implant has provided a high level of prosthetic predictability.     

Early loading of Osseotite implants 2 months after placement in the maxilla and mandible: a 5-year report

PURPOSE: In this multicenter study, the performance of Osseotite implants after a 1-stage surgery and abbreviated healing period of 2 months is reported. The implants were followed for up to 5 years. MATERIALS AND METHODS: Partially or completely edentulous patients treated at 10 private practice centers were included in the study. Oral hygiene was assessed using the plaque index and the gingival index prior to surgery and at recall visits at 6 months, 1, 2, 3, 4, and 5 years after initial loading. Bone density and implant/bone fit were evaluated at the time of surgery. Implants were loaded after a healing period of about 2 months. RESULTS: The mean age of the patients at time of enrollment was 60.4 +/- 13.0 years; 44% (86) of the patients were men and 56% (109) were women. In all, 526 implants were placed, 65.4% in the mandible and 34.6% in the maxilla, with 23.0% placed in anterior locations and 77.0% in the posterior. The cumulative success rate of these 526 implants was 97.9% at 5 years. Eight of the 11 implant failures occurred during nonsubmerged healing prior to prosthetic loading. Provisional restorations were placed at 2.1 +/- 0.5 months, at which time implants were evaluated for mobility, gingival health, symptomology, and radiolucency. The distribution of prosthesis types included 118 single-tooth restorations (118 implants), 134 short-span prostheses (327 implants), and 16 long-span restorations (81 implants). DISCUSSION: The benefits of early loading cannot be fully appreciated if there is a substantive increase in implant failures. In this study, a cumulative success rate greater than 97% was maintained throughout 5 years of observation. CONCLUSION: These results suggest that success can be expected with Osseotite implants after a nonsubmerged reduced healing period of 2 months in this patient population.     

Long-term performance of Osseotite implants: a 6-year clinical follow-up

In this prospective, multicenter study, 147 Osseotite implants were placed in 75 patients (32 men and 43 women with a mean age of 54 years) using a conventional two-stage surgical protocol with 3 months of healing time in the mandible and 6 months in the maxilla. Of the 147 implants, 69% were inserted in posterior sites and 64% were short implants of 10 mm or less. From the time of implant insertion to second-stage surgery, 5.1 months (+/- 2.4 months) elapsed. Restorative treatments included 25 single-tooth replacements (28.4%), 58 short span fixed bridges (65.9%), 1 full-arch reconstruction (1.1%), and 4 overdentures (4.5%). The mean time from implant placement to final recall was 74.1 months (+/- 8.9 months). At second-stage surgery and at 6-month and annual follow-up examinations, implants were evaluated for mobility, peri-implant radiolucency, gingival health, signs and symptoms of infection, neuropathies, paresthesia, and crestal bone levels. A 3-year interim report identified 5 implant failures, 4 of which occurred as a clustering phenomenon in a single, medically compromised patient. Using the life table analysis method, the cumulative implant success rate was calculated at 96.6%. The 3-year interim report indicates that the implants developed an extended, functional osseous state that remained stable for more than 6 years.     

A prospective multicenter clinical investigation of a bone quality-based dental implant system

This article reports the 5-year interim results of an independently monitored, prospective, multicenter clinical trial of a bone quality-based implant design. At six study centers, 495 implants were placed in 151 cases with an average follow-up period of 1.6 years (range: 1.0-3.6 years) after prosthesis delivery. The majority of the implants were placed in D2 or D3 bone to support fixed partial dentures or implant-supported overdentures. Using strict success criteria, there were three implant failures, resulting in a cumulative 99.5% success rate according to Kaplan-Meier survival analysis. Radiographic analysis revealed a mean bone loss of 0.06 mm at 1 year and a bone gain of 0.04 mm at 2 years after prosthesis loading. There were no statistical differences in the results by center, implant type, bone density, area of the mouth, or prosthesis type. The results of this 5-year study revealed a high success rate and limited crestal bone loss in all bone densities by the use of an implant specifically designed for the varying biomechanical conditions and bone quality associated with the human maxilla and mandible.     

A human histologic analysis of osseotite and machined surfaces using implants with 2 opposing surfaces

A human histologic study was conducted to compare the percentage of bone-to-implant contact (BIC) at 6 months for Osseotite and machined, commercially pure titanium implant surfaces. To eliminate potential influences caused by differences in bone density at different intraoral locations, 2 mm x 5 mm, threaded, 2-surfaced titanium implants were manufactured; 1 side received the Osseotite surface modification and the opposite side maintained a machined surface. In each of 11 patients, 1 test implant was placed in the posterior maxilla (Types III and IV bone) during conventional dental implant surgery. Following 6 months of unloaded healing, the conventional implants were uncovered, and the test implants and surrounding hard tissue were removed. Histologic analysis indicated that at 6 months of unloaded healing, the mean BIC value for the Osseotite surfaces (72.96% +/- 25.13%) was statistically significantly higher (P < 0.05) than the mean BIC value for the machined surfaces (33.98% +/- 31.04%). When the BIC values for the machined and Osseotite surface pairs were ranked from high to low based on the machined BIC value range of 93% to 0%, the upper 50th percentile (20 surface pairs) mean BIC value was 86.1% +/- 16.7% for the Osseotite surfaces and 60.1% +/- 18.3% for the machined surfaces. The lower 50th percentile (19 surface pairs) mean BIC value was 59.1% +/- 25.3% for the Osseotite surfaces and 6.5% +/- 10.8% for the machined surfaces. Differences between mean BIC values for the 2 surfaces in both the upper and lower 50th percentiles were statistically significant (P < 0.05). The results of this study indicate that in the poorer quality bone typically found in the posterior maxilla, a statistically significantly higher percentage of bone contacts Osseotite surfaces when compared to opposing machined surfaces on the same implant.     

Immediate occlusal loading the same day or the after implant placement: comparison of 2 different time frames in total edentulous lower jaws

Immediate loading of endosseous implants is becoming a widespread therapeutic procedure for the rehabilitation of patients with edentulous jaws. The purpose of this prospective clinical trial was to evaluate the long-term success rate of endosseous implants placed in the edentulous lower jaw and loaded on either the same day of surgery or the next day. Nineteen patients were enrolled in the study. Eleven patients, accounting for 64 implants, received their provisional prosthesis the same day of implant placement, and 8 patients, accounting for 52 implants, were rehabilitated the day after surgery. All patients were rehabilitated by a hybrid prosthesis supported by 5 to 6 Osseotite implants. Two implants failed in the group of patients who had their implants loaded the same day (96.9% success rate), whereas 1 implant failed in the other group (98.1% success rate). The overall implant success rate was 97.4%. All failures occurred within 2 months of function. No other complication was reported. The mean follow-up for this interim report was 37.8 +/- 16.5 months (range 8-65 months). Crestal bone loss was similar to that reported for standard delayed loading protocols. The results of this study suggest that the rehabilitation of the edentulous lower jaw by an immediate occlusally loaded implant-supported hybrid prosthesis is equally successful when loading is applied the same day or the day after implant placement. Immediate loading with 5 to 6 implant-supported prostheses represents a viable alternative treatment to classic delayed loading protocols.     

Osseotite implant: 3-year prospective multicenter evaluation

Purpose : This prospective multicenter study evaluates the cumulative success rate of the Osseotite® implant after 3 years of prosthetic loading.
Materials and Methods : A total of 413 Osseotite® implants (Implant Innovations®) were placed in 142 patients (completely or partially edentulous) in five dental offices exclusively devoted to implants. The average age of the patients was 58.3 years. Of the 413 implants, 191 were placed in the maxilla and 222 in the mandible; 271 (65.6%) were posterior implants and 142 (34.4%) were anterior implants. Clinical and radiographic evaluations were made after completion of the prosthetic restoration, after 6 months of loading, at 1 year, and at 3 years.
Results : A cumulative success rate of 95.3% was obtained after 3 years of prosthetic loading. The success rate was similar in both arches: 95.1% in the maxilla and 96.8% in the mandible. Early failures (before prosthetic loading) were greater (n = 12) than late failures (n = 2). After 3 years of prosthetic loading, the marginal bone level of 385 (93.2%) implants were evaluated radiographically. Bone level was at the first thread for 91.4% of the implants. A slightly increased loss was observed around 26 implants (6.7%). Including survival implants, the cumulative implant success rate after 3 years was 96%. A success rate of 98.4% was obtained with 187 short implants (8, 5 and 10 mm) reported in this multicenter evaluation.
Conclusion : This multicenter evaluation demonstrates excellent predictability for Osseotite implants.     

A prospective multicenter clinical trial of 3i machined-surface implants: results after 6 years of follow-up

PURPOSE: In this prospective multicenter clinical study, 1,179 3i standard threaded and self-tapping implants were followed for up to 6 years and monitored according to established success criteria. MATERIALS AND METHODS: A total of 493 patients (240 men and 253 women) with a mean age of 45.1 years at implant surgery were enrolled at 6 research centers after being screened for exclusion criteria. Implants were placed according to a 2-stage surgical protocol with a minimum of 4 months of submerged healing in the mandible and 6 months in the maxilla. Restorations included 633 prostheses, the majority of which were fixed partial dentures in the posterior mandible or maxilla or single-tooth replacements in the anterior maxilla. RESULTS: One hundred four implants (8.8%) did not meet success criteria and were designated as failures, and 222 implants (18.8%) were lost to follow-up. The cumulative success rate according to life table methods was 91.1% at 6 years. DISCUSSION: Sixty percent of the failed implants were short (< or = 10 mm long), and their cumulative success rate as a group at 6 years was 89.0%, compared to 93.1% for longer implants (P < .05). Thirty-three percent of all failures were implants placed in the posterior maxilla, for a 5-year cumulative success rate of 87.4%. CONCLUSION: It appears that limited bone dimensions and poor-quality bone have an impact on the performance of these machined-surface implants.     

Tilting of posterior mandibular and maxillary implants for improved prosthesis support

Rehabilitation of atrophied edentulous arches with endosseous implants in the posterior regions is often associated with anatomic problems such as jaw shape and location of the mental loop, mandibular canal, and maxillary sinuses. The purpose of this investigation was to modify the method for implant placement in the posterior part of the jaws to extend fixed implant-connected prostheses further distally, and to reduce the length of cantilevers in complete-arch prostheses without transpositioning the mandibular nerve or performing bone grafting in the maxilla. Forty-seven consecutive patients were treated with implants (25 patients/36 mandibular implants, 22 patients/30 maxillary implants) placed in tilted positions. They were followed a mean of 40 months (mandibles) and 53 months (maxillae). In the mandible, implants close to the mental foramina were tilted posteriorly approximately 25 to 35 degrees. In the maxilla, the posterior implants were placed close to and parallel with the sinus walls and were titled anteriorly/posteriorly approximately 30 to 35 degrees. Patients gained a mean distance of 6.5 mm of prosthesis support in the mandible and 9.3 mm in the maxilla, as a result of implant tilting. There were no implant failures in mandibles. The cumulative success rates in the maxilla at 5 years were 98% for tilted implants and 93% for non-tilted implants. Paresthesias of the mental nerve were observed on 4 sides during the first 2 to 3 weeks after implant placement. Analysis of the load distribution in one mandibular case showed no significant difference between tilted and the non-tilted implants, and the improved prosthesis support was confirmed. Satisfactory medium-term results concerning osseointegration and significant extension of prosthesis support show that the method can be recommended. This technique may allow for longer implants to be placed with improved bone anchorage.     

Retrospective clinical study of Osseotite implants: zero- to 5-year results

PURPOSE: Over the last few years, particular attention has been paid to the implant surface and its influence on the formation and maintenance of surrounding bone. The surface of Osseotite implants (Implant Innovations) is produced by a process of thermal etching, which produces a surface with an average roughness that is twice that of machined implants produced by the same manufacturer. In addition to reducing osseointegration time, this factor appears to favor its maintenance over time. This study presents the results of a clinical trial of Osseotite implants. MATERIALS AND METHODS: Five hundred fifty-five Osseotite implants were placed in 244 patients over 5 years, between September 1996 and September 2001. The average follow-up period from implant placement was 26 months (SD 13.1). RESULTS: After the first surgical stage, 8 failures were noted in 6 patients. Life table analysis showed a cumulative survival rate of 98.5%, but no implant was lost after prosthetic loading, with a 100% survival rate both for the mandible and for the maxilla. For the prosthetic loading time, only the implants with more than 12 months of loading were considered, obtaining an average prosthetic loading time of 34 months (SD 9.2). DISCUS SION: The implant survival rate after loading was 100% both in the anterior and posterior regions, and no difference was noted in relation to the different types of prostheses, or length and width of implants. CONCLUSION: The results obtained in this retrospective study population revealed an acceptable survival rate for these implant-supported restorations.     

Early outcome of an implant system with a resorbable adhesive calcium–phosphate coating—a prospective clinical study in partially dentate patients

This study aims to investigate the early outcome of a dental implant with bioactive calcium-phosphate (CaP) coating in the first year of usage in different clinical indications in partially edentulous patients, after early and delayed prosthetic loading. Therefore, in a prospective follow-up study, the cumulative survival and success rate of a conical, self-drilling and self-tapping implant system after 6 months and 1 year post-insertion was evaluated. A total of 311 CaP-coated implants were placed in 124 patients. Seventy-two implants in clinical high-quality bone situation were loaded after 2 weeks post-insertion with the definite restoration; the rest after 6 months. The indication for implant placement was treatment of partial dentate mandible and maxilla. One hundred sixty-three implants were placed in the posterior mandible, 117 in the posterior maxilla. In the frontal maxilla, 25 implants and in the frontal mandible, eight implants were used. In 126 cases (36%), bone augmentation procedures (guided bone regeneration and sinus lift) were performed concomitant with implant placement. The difference between primary and secondary stability (implant stability quotient (ISQ), Periotest, insertion torque), peri-implant clinical parameter as well as survival and success criteria were evaluated. In total, ISQ mean values after 6 months were higher than after implant placement. Periotest values increased in the period of the first 6 months and remained constant afterwards. After 6 months of insertion, the mean bone loss was 0.051 mm. After 12 months, a bone gain with a mean of +0.016 mm was observed; implants in the posterior maxilla showed significant less bone resorption than implants in the posterior mandible (p < 0.0001). In the most of the implants (74%), clinical normal gingival tissue could be observed. In 24%, a mild inflammation was analysed. In 35 implants, a provocation of peri-implant bleeding was possible. In the early loading group, no implant failure was seen. Altogether, one implant in D4 bone has been lost. The cumulative survival rate summed up to 99.7%. In general, implant success assessment analysis according to Albrektsson and Buser displayed success in 99.7% of the implants. With respect to the patient selection including 124 implants with minor and major augmentations as well as early loading prosthetic function, the 1-year clinical use of the studied implant system with CaP coating showed good results, comparable to that of conventional implants without a specific coating. After 1 year, neither special disadvantages nor benefits of CaP-coated implants could be evaluated. Long-term results are further needed.     

Immediate loading of osseotite implants: two-year results

The high success rate of dental implants has changed the quality of life for many patients. Immediate loading finds its application in some clinical cases and certainly adds another modality of treatment for the implant patient. Starting with a couple of implants placed in the mandible and immediately loaded within 72 hours after surgical placement with an overdenture, this concept evolved to immediately loading multiple implants in both the maxilla and the mandible. In this investigation, 11 consecutive patients were treated with 87 screw-shaped endosteal acid-etched, Osseotite implants (3i, Implant Innovations, Inc., Palm Beach Gardens, FL) between June 1998 and June 1999. Two mandibular and two maxillary cases received screw-retained provisional prostheses the day of surgery. Three mandibular and four maxillary cases were loaded 48 hours after surgery with the final screw-retained, porcelain-fused-to-metal prostheses. All implants were followed for 2 to 3 years. Follow-up consisted of clinical as well as radiographic examination. All implants were successful. There was no implant mobility or periimplant radiolucency. The bone level was measured at the 12th and 24th months. The average radiographic bone level from the implant platform to the first bone-to-implant contact was 0.654 mm at the 12th month and 0.946 mm at the 24th month. We conclude that a high success rate can be achieved when implants with a hybrid surface, machined/acid-etched, are immediately loaded within 48 hours after surgical placement in the maxilla and the mandible.     

A multicenter prospective evaluation of 2-months loaded Osseotite implants placed in the posterior jaws: 3-year follow-up results

Abstract: In this prospective study, the clinical outcome of 2‐months loaded implants placed in the posterior jaws was evaluated after up to 3 years of functional loading. 405 Osseotite^® implants with microtextured acid‐etched surface were consecutively placed in 11 fully and 164 partially edentulous patients (mean age 53.5± 15.3 (S.D.) years) using a one‐stage technique. 282 implants, supporting 154 restorations, were placed in the mandible, while 123 implants, supporting 75 restorations, were placed in the maxilla. A total of 99 single‐tooth restorations, 119 short‐span fixed bridges and 11 full‐arch prostheses were applied. The mean time interval from surgery to connection of provisional restoration was 2.0±0.7 months. 9 failures were reported up to 3 years of follow‐up; of these, 4 mandibular and 2 maxillary implants failed during the initial healing period (before prosthesis connection), while 3 mandibular implants failed after loading. No other complications occurred throughout the study. Life table analysis showed a cumulative survival rate of 97.5% for the mandible and 98.4% for the maxilla. Post‐loading implant survival rate was 98.9% for the mandible and 100% for the maxilla. The excellent outcome of this interim report suggests that microtextured Osseotite^® implants in the posterior jaws may safely bear a functional load applied 2 months after insertion. The results of the present study are particularly encouraging for implants placed in the maxilla, since both a significant reduction of the healing period compared to the 6 months suggested by the classical Brånemark protocol, and an excellent post‐loading function may be achieved also in low quality bone.     

Immediate occlusal loading of Osseotite implants in the lower edentulous jaw. A multicenter prospective study

OBJECTIVE: This paper reports the results of a prospective multicenter clinical study on immediately fully occlusally loaded full-arch screw-retained prostheses with distal extensions (hybrid prostheses) supported by Osseotite implants inserted in edentulous lower jaws. METHOD AND MATERIAL: Sixty-two patients were enrolled in four clinical centers. Three hundred and twenty-five Osseotite implants were inserted and occlusally loaded according to an immediate loading protocol. The temporary prosthesis was delivered 4 h from surgery. The final prosthesis was delivered after 6 months. Marginal bone loss was monitored from periapical radiographs using a computerized technique. RESULTS: Two implants failed to integrate within 2 months of occlusal loading. A cumulative implant success rate of 99.4% was achieved for a period of 12-60 months postplacement (mean 28.6+/-14.1 (SD) months). Crestal bone loss around the immediately loaded implants was similar to that reported for standard delayed loading protocols. CONCLUSION: The results of this study suggest that the rehabilitation of the edentulous mandible by an immediate occlusally loaded hybrid prosthesis supported by five to six Osseotite implants represents a viable alternative treatment to classic delayed loading protocols.     

A 3-arm study of early loading of rough-surfaced implants in the completely edentulous maxilla and in the edentulous posterior maxilla and mandible: results after 1 year of loading

PURPOSE: The aim of the present prospective study was to evaluate the concept of early loading of rough-surfaced implants in the completely edentulous maxilla and in the edentulous posterior mandible and maxilla. MATERIALS AND METHODS: Fifty-four consecutive patients were treated. Twenty patients were completely edentulous in the maxilla (group A), 19 patients were edentulous in the posterior left and/or right maxilla (group B), and 15 patients were edentulous in the posterior left and/or right mandible (group C). One patient in group B and 5 in group C were bilaterally treated. Two hundred thirty-four solid screw-type, sandblasted, large-grit, acid-etched (SLA) ITI implants were placed, 58 (25%) immediately after tooth extraction. Mean placement torque and standard deviations were measured at all sites. Sixty fixed prostheses were delivered after a mean delay of 9 days (range, 4 to 22 days). Mean marginal bone reduction was measured after 1 year of loading. RESULTS: Two implants were lost (0.9%), 1 before functional loading and 1 after 1 year. All other implants were clinically stable, with a mean marginal bone loss of 0.75 mm (+/-1.3 mm). Marginal bone loss ranged from 0 to 3.5 mm. Mean placement torque on implants placed in healed bone or immediately after tooth extraction ranged from 29.1+/-9.3 Ncm to 35.5+/-5.8 Ncm. No statistical difference was found (P > .05) between implants placed in healed bone and those placed immediately after tooth extraction. DISCUSSION: There is little documentation for immediate or early loading in the areas studied. However, in this study, favorable results were obtained in 54 consecutive patients in these regions. CONCLUSION: In this study population, early loading protocols can be applied with predictable results using rough-surfaced implants for rehabilitation of the completely edentulous maxilla, posterior maxilla, and posterior mandible.     

Radiographic evaluation of dental implants placed using an osteotome technique

BACKGROUND: The osteotome technique has been successfully used for implant placement when a limited vertical height is available at posterior maxilla. However, it is not clear if new bone is formed at the apical portion of the implant placed by this technique without any bone graft. The aim of this study was to radiographically evaluate bone formation around dental implant surfaces exposed to the space created at the sinus floor without the presence of any graft material. METHODS: Forty patients (21 male, 19 female; mean age 46.7 years) who received a total of 75 dental implants together with indirect sinus lifting procedure were included. Initial and 6-month postoperative panoramic films were scanned and analyzed using a commercially available software program. Implants were divided into two groups: initial alveolar bone height <9 mm or > or =9 mm. This helped determine the effect of available bone and exposed implant surface on bone formation in a system where the shortest implant was 8 mm. RESULTS: The mean implant length placed at locations with <9 mm initial bone height (mean 7 +/- 1.3 mm, N = 29 implants) was 11 +/- 1.7 mm; gain in bone height was 3.9 +/- 1.9 mm. At locations where minimum bone height was 9 mm (mean 10.4 +/- 0.7 mm), 44 implants were placed with a 13.5 +/- 1.06 mm mean length. Mean gain in bone height was 2.9 +/- 1.2 mm at these sites. Two implants were lost at stage 2 surgery. The success rate after 25 months of loading was 97.3%. CONCLUSIONS: It is possible to radiographically observe a gain of approximately 3 to 4 mm of bone from the sinus floor to the implant apex. The amount of initial alveolar bone height, presence of sinus membrane perforation, and the amount of exposed implant surface appear to play a role in the presence or absence of radiopacity within the elevated sinus floor, following 6 months of healing.     

A prospective,multicenter, 4-year study of the ACE Surgical resorbable blast media implant

This article reports on the 50-month results of the evaluation of the ACE Surgical resorbable blast media (RBM) dental implant. There were 1077 implants placed in 348 patients: 950 in the mandible and 127 in the maxilla. A total of 78.6% of the implants were used to support anterior, mandibular, bar-retained overdentures. The 3.75- to 4.00-mm-diameter implant was used in 91.1% of cases, with the remainder being 3.3 mm (2.2%) or 4.75 mm (6.7%). The implants of 10-, 13-, and 15-mm lengths were used in almost equal amounts in the mandible, maxilla, and anterior or posterior aspects of either jaw. There were 7 failures, all in the mandible and before stage 2 surgery. The overall implant success rate in this 50-month interim report is 99.3% in the mandible and 100% for the maxilla. There was no discernible crestal bone loss during the study period. No differences in bone response were seen in RBM implants with roughened surfaces on the entire implant, up to the collar, or up to the first 2 threads below the collar.     

Immediate function with fixed implant-supported maxillary dentures: a 12-month pilot study

STATEMENT OF PROBLEM: Immediate occlusal loading of dental implants in the edentulous mandible has proven to be an effective, reliable, and predictable procedure. There is little long-term data available on similar treatments in the edentulous maxilla. PURPOSE: The purpose of this study was to evaluate the 12-month implant survival after immediate loading of 4 to 6 implants with fixed screw-retained prostheses in edentulous maxillae. MATERIAL AND METHODS: Twenty-one patients, edentulous or with remaining teeth to be extracted in the maxilla, received 4 to 6 implants (n=111). The patients were restored with screw-retained fixed provisional prostheses supported by palladium-alloy frameworks within 24 hours after surgery. Insertion torques for implants were at least 40 Ncm. Implants, grouped as tapered or cylindrical screws, were placed in healed bone or extraction sockets. Implants were also classified as either vertical or off-angle. Definitive prostheses were placed after a mean healing time of 18 weeks. Radiographic examinations were made at the time of placement of provisional prostheses and 12 months later. Between-groups bone resorption was compared using 2-way ANOVA (alpha=.05). RESULTS: The mean follow-up time for all of the patients was 20 months (range, 13 to 28 months). The cumulative implant survival rate at the 12-month follow-up visits (after surgery) was 92.8%; the prostheses survival rate was 100%. No significant differences were found between the survival of tapered or cylindrical screw-type implants placed in postextraction sockets versus those in healed edentulous sites or between vertical and off-angle placed implants. Eight implants failed during the first 3 months, 5 of which were the most distal implants. The mean reduction in marginal bone height over the 12-month observation period was 0.84 mm (CI 95%; 0.68-0.99 mm). CONCLUSIONS: In this study with 12-month follow-up, 4 to 6 implants were sufficient to successfully support fixed implant screw-retained prostheses in the edentulous maxillae of 21 patients.     

A prospective study of treatment of severely resorbed maxillae with narrow nonsubmerged implants: results after 1 year of loading.

The aim of the present study was to evaluate the use of reduced-diameter implants as an alternative to bone grafting for treatment of patients with severely resorbed maxillae. Forty patients (25 females, 15 males, mean age of 57 years, range 19 to 86) with insufficient bone volume for placement of standard-size implants in the maxilla (31 totally edentulous) were treated with 3.3-mm-diameter implants (ITI, titanium plasma-sprayed solid screws). Augmentation was considered for all patients because of lack of sufficient bone volume. Preoperative radiographic examination showed that in all cases, the height of the alveolar crest with a width of 4 mm was less than 10 mm. A total of 182 implants with a length of 8 to 12 mm were placed. All but 3 patients planned for overdenture treatment received fixed prostheses or single crowns (n = 3). One implant (8 mm long) was lost 1 month after placement, providing a survival rate of 99.4% after 1 year of loading. Since 4 implants with peri-implantitis were successfully treated and 1 implant left as a "sleeper" because of malposition, the cumulative success rate was 96.4%. The mean marginal bone resorption at baseline was 0.14 +/- 0.67 mm (range 0 to 6 mm). After 1 year of loading the mean resorption was 0.35 +/- 1.05 mm (range 0 to 7 mm); 4.8% of the implants had marginal bone resorption of more than 2 mm.